Laser-induced phonon amplification in a single-walled nanotube

China Center of Advanced Science and Technology - P.O. Box 8730 Beijing 100080, PRC and Physics Department, Beijing University of Science and Technology Beijing 100083, PRC

Received: 8 July 2005
Accepted: 2 November 2005

Abstract

In this work, we present a phonon amplification effect occurring in a single-walled nanotube in the presence of a laser field. We calculate the rate of change of the phonon population and obtain the field strength threshold for achieving the phonon amplification. The optical phonon population is seen to increase nonlinearly provided the phonon growth rate is greater than the phonon loss. We find that the intense laser field can open a window of generating phonon amplification in the one-dimensional wave vector space parallel to the tube axis.